Nana's Banana Bread

(not my nana, just the name it came with!)
5 TBSP butter
1/2 cup sugar
1/2 packed brown sugar
1 large egg
2 egg whites
1 tsp vanilla
1 1/2 cups mashed bananas
1 3/4 cups flour
1 tsp baking soda
1/2 tsp salt
1/4 tsp baking powder
1/2 cup heavy cream
1/3 cup walnuts

Preheat oven to 350 degrees. Spray bottom only of 9x5x3 in loaf pan with nonstick cooking spray.

Beat butter in large bowl with an electric mixer set at medium speed until light and fluffy. Add sugar and brown sugar, beat well. Add egg, egg whites and vanilla; beat until well blended. Add mashed banana, and beat on high speed 30 seconds.

Combine flour, baking soda, salt and baking powder in medium bowl. Add flour mixture to butter mixture alternatly with cream, ending with flour mixture. Add walnuts to batter; mix well.

Pour batter evenly into prepared loaf pan. Bake until browned and toothpick inserted near center comes out clean, about 1 hour 15 min.

Cook bread in pan on wire rack 10 minutes. Remove bread from pan; cool completely on wire rack. Slice and serve with butter and jam.